drivers/iio/temperature/tmp006.c

   1 /*
   2  * tmp006.c - Support for TI TMP006 IR thermopile sensor
   3  *
   4  * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License.  See the file COPYING in the main
   8  * directory of this archive for more details.
   9  *
  10  * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
  11  *
  12  * (7-bit I2C slave address 0x40, changeable via ADR pins)
  13  *
  14  * TODO: data ready irq
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/i2c.h>
  19 #include <linux/delay.h>
  20 #include <linux/module.h>
  21 #include <linux/pm.h>
  22 #include <linux/bitops.h>
  23
  24 #include <linux/iio/iio.h>
  25 #include <linux/iio/sysfs.h>
  26
  27 #define TMP006_VOBJECT 0x00
  28 #define TMP006_TAMBIENT 0x01
  29 #define TMP006_CONFIG 0x02
  30 #define TMP006_MANUFACTURER_ID 0xfe
  31 #define TMP006_DEVICE_ID 0xff
  32
  33 #define TMP006_TAMBIENT_SHIFT 2
  34
  35 #define TMP006_CONFIG_RESET BIT(15)
  36 #define TMP006_CONFIG_DRDY_EN BIT(8)
  37 #define TMP006_CONFIG_DRDY BIT(7)
  38
  39 #define TMP006_CONFIG_MOD_MASK 0x7000
  40
  41 #define TMP006_CONFIG_CR_MASK 0x0e00
  42 #define TMP006_CONFIG_CR_SHIFT 9
  43
  44 #define MANUFACTURER_MAGIC 0x5449
  45 #define DEVICE_MAGIC 0x0067
  46
  47 struct tmp006_data {
  48         struct i2c_client *client;
  49         u16 config;
  50 };
  51
  52 static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)
  53 {
  54         s32 ret;
  55         int tries = 50;
  56
  57         while (tries-- > 0) {
  58                 ret = i2c_smbus_read_word_swapped(data->client,
  59                         TMP006_CONFIG);
  60                 if (ret < 0)
  61                         return ret;
  62                 if (ret & TMP006_CONFIG_DRDY)
  63                         break;
  64                 msleep(100);
  65         }
  66
  67         if (tries < 0)
  68                 return -EIO;
  69
  70         return i2c_smbus_read_word_swapped(data->client, reg);
  71 }
  72
  73 static const int tmp006_freqs[5][2] = { {4, 0}, {2, 0}, {1, 0},
  74                                         {0, 500000}, {0, 250000} };
  75
  76 static int tmp006_read_raw(struct iio_dev *indio_dev,
  77                             struct iio_chan_spec const *channel, int *val,
  78                             int *val2, long mask)
  79 {
  80         struct tmp006_data *data = iio_priv(indio_dev);
  81         s32 ret;
  82         int cr;
  83
  84         switch (mask) {
  85         case IIO_CHAN_INFO_RAW:
  86                 if (channel->type == IIO_VOLTAGE) {
  87                         /* LSB is 156.25 nV */
  88                         ret = tmp006_read_measurement(data, TMP006_VOBJECT);
  89                         if (ret < 0)
  90                                 return ret;
  91                         *val = sign_extend32(ret, 15);
  92                 } else if (channel->type == IIO_TEMP) {
  93                         /* LSB is 0.03125 degrees Celsius */
  94                         ret = tmp006_read_measurement(data, TMP006_TAMBIENT);
  95                         if (ret < 0)
  96                                 return ret;
  97                         *val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;
  98                 } else {
  99                         break;
 100                 }
 101                 return IIO_VAL_INT;
 102         case IIO_CHAN_INFO_SCALE:
 103                 if (channel->type == IIO_VOLTAGE) {
 104                         *val = 0;
 105                         *val2 = 156250;
 106                 } else if (channel->type == IIO_TEMP) {
 107                         *val = 31;
 108                         *val2 = 250000;
 109                 } else {
 110                         break;
 111                 }
 112                 return IIO_VAL_INT_PLUS_MICRO;
 113         case IIO_CHAN_INFO_SAMP_FREQ:
 114                 cr = (data->config & TMP006_CONFIG_CR_MASK)
 115                         >> TMP006_CONFIG_CR_SHIFT;
 116                 *val = tmp006_freqs[cr][0];
 117                 *val2 = tmp006_freqs[cr][1];
 118                 return IIO_VAL_INT_PLUS_MICRO;
 119         default:
 120                 break;
 121         }
 122
 123         return -EINVAL;
 124 }
 125
 126 static int tmp006_write_raw(struct iio_dev *indio_dev,
 127                             struct iio_chan_spec const *chan,
 128                             int val,
 129                             int val2,
 130                             long mask)
 131 {
 132         struct tmp006_data *data = iio_priv(indio_dev);
 133         int i;
 134
 135         for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)
 136                 if ((val == tmp006_freqs[i][0]) &&
 137                     (val2 == tmp006_freqs[i][1])) {
 138                         data->config &= ~TMP006_CONFIG_CR_MASK;
 139                         data->config |= i << TMP006_CONFIG_CR_SHIFT;
 140
 141                         return i2c_smbus_write_word_swapped(data->client,
 142                                                             TMP006_CONFIG,
 143                                                             data->config);
 144
 145                 }
 146         return -EINVAL;
 147 }
 148
 149 static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
 150
 151 static struct attribute *tmp006_attributes[] = {
 152         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 153         NULL
 154 };
 155
 156 static const struct attribute_group tmp006_attribute_group = {
 157         .attrs = tmp006_attributes,
 158 };
 159
 160 static const struct iio_chan_spec tmp006_channels[] = {
 161         {
 162                 .type = IIO_VOLTAGE,
 163                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 164                         BIT(IIO_CHAN_INFO_SCALE),
 165                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 166         },
 167         {
 168                 .type = IIO_TEMP,
 169                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 170                         BIT(IIO_CHAN_INFO_SCALE),
 171                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 172         }
 173 };
 174
 175 static const struct iio_info tmp006_info = {
 176         .read_raw = tmp006_read_raw,
 177         .write_raw = tmp006_write_raw,
 178         .attrs = &tmp006_attribute_group,
 179         .driver_module = THIS_MODULE,
 180 };
 181
 182 static bool tmp006_check_identification(struct i2c_client *client)
 183 {
 184         int mid, did;
 185
 186         mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);
 187         if (mid < 0)
 188                 return false;
 189
 190         did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);
 191         if (did < 0)
 192                 return false;
 193
 194         return mid == MANUFACTURER_MAGIC && did == DEVICE_MAGIC;
 195 }
 196
 197 static int tmp006_probe(struct i2c_client *client,
 198                          const struct i2c_device_id *id)
 199 {
 200         struct iio_dev *indio_dev;
 201         struct tmp006_data *data;
 202         int ret;
 203
 204         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 205                 return -ENODEV;
 206
 207         if (!tmp006_check_identification(client)) {
 208                 dev_err(&client->dev, "no TMP006 sensor\n");
 209                 return -ENODEV;
 210         }
 211
 212         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 213         if (!indio_dev)
 214                 return -ENOMEM;
 215
 216         data = iio_priv(indio_dev);
 217         i2c_set_clientdata(client, indio_dev);
 218         data->client = client;
 219
 220         indio_dev->dev.parent = &client->dev;
 221         indio_dev->name = dev_name(&client->dev);
 222         indio_dev->modes = INDIO_DIRECT_MODE;
 223         indio_dev->info = &tmp006_info;
 224
 225         indio_dev->channels = tmp006_channels;
 226         indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);
 227
 228         ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);
 229         if (ret < 0)
 230                 return ret;
 231         data->config = ret;
 232
 233         return iio_device_register(indio_dev);
 234 }
 235
 236 static int tmp006_powerdown(struct tmp006_data *data)
 237 {
 238         return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 239                 data->config & ~TMP006_CONFIG_MOD_MASK);
 240 }
 241
 242 static int tmp006_remove(struct i2c_client *client)
 243 {
 244         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 245
 246         iio_device_unregister(indio_dev);
 247         tmp006_powerdown(iio_priv(indio_dev));
 248
 249         return 0;
 250 }
 251
 252 #ifdef CONFIG_PM_SLEEP
 253 static int tmp006_suspend(struct device *dev)
 254 {
 255         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 256         return tmp006_powerdown(iio_priv(indio_dev));
 257 }
 258
 259 static int tmp006_resume(struct device *dev)
 260 {
 261         struct tmp006_data *data = iio_priv(i2c_get_clientdata(
 262                 to_i2c_client(dev)));
 263         return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 264                 data->config | TMP006_CONFIG_MOD_MASK);
 265 }
 266 #endif
 267
 268 static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);
 269
 270 static const struct i2c_device_id tmp006_id[] = {
 271         { "tmp006", 0 },
 272         { }
 273 };
 274 MODULE_DEVICE_TABLE(i2c, tmp006_id);
 275
 276 static struct i2c_driver tmp006_driver = {
 277         .driver = {
 278                 .name   = "tmp006",
 279                 .pm     = &tmp006_pm_ops,
 280                 .owner  = THIS_MODULE,
 281         },
 282         .probe = tmp006_probe,
 283         .remove = tmp006_remove,
 284         .id_table = tmp006_id,
 285 };
 286 module_i2c_driver(tmp006_driver);
 287
 288 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 289 MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");
 290 MODULE_LICENSE("GPL");